U.S. patent number 5,682,434 [Application Number 08/480,231] was granted by the patent office on 1997-10-28 for wearable audio system with enhanced performance.
This patent grant is currently assigned to Interval Research Corporation. Invention is credited to James H. Boyden.
United States Patent |
5,682,434 |
Boyden |
October 28, 1997 |
**Please see images for:
( Certificate of Correction ) ** |
Wearable audio system with enhanced performance
Abstract
A wearable portable entertainment and personal communication
system which provides high quality sound, particularly at low audio
frequencies, and which does not block or attenuate environmental
sounds is disclosed. In a first embodiment, a transducer or
transducer array is positioned on a wall in a sampling chamber
between two cavities. One of the cavities is sealed and the other
has one or more conduit members which direct the acoustic signals
to one or both of the wearer's ears. In a second embodiment, both
cavities have conduits, one directed to each of the wearer's ears.
With either embodiment, the sampling chamber optionally can be
combined with separate high frequency transducers. With both
embodiments, the chambers are incorporated into a wearable garment
and the transducers are connected to a source of audio signals.
Inventors: |
Boyden; James H. (Los Altos
Hills, CA) |
Assignee: |
Interval Research Corporation
(Palo Alto, CA)
|
Family
ID: |
23907180 |
Appl.
No.: |
08/480,231 |
Filed: |
June 7, 1995 |
Current U.S.
Class: |
381/385;
381/386 |
Current CPC
Class: |
H04M
1/05 (20130101); H04M 9/00 (20130101); H04R
5/023 (20130101); H04R 2201/023 (20130101) |
Current International
Class: |
H04M
1/05 (20060101); H04R 5/02 (20060101); H04M
1/04 (20060101); H04M 9/00 (20060101); H04R
025/00 () |
Field of
Search: |
;381/24,25,187,188,68.5
;455/89 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kuntz; Curtis
Assistant Examiner: Barnie; Rexford N.
Attorney, Agent or Firm: Brooks & Kushman
Claims
It is claimed:
1. An audio system for producing high fidelity audio signals and
adapted to be worn on the torso of a wearer, the audio signals
including high frequency signals and low frequency signals, said
audio system comprising:
at least one housing having at least two chambers with a common
wall member separating said two chambers,
first output transducer means mounted on said common wall
member,
a source of high fidelity audio signals,
means connecting said source of audio signals to said first
transducer means for driving said transducer means and producing
low frequency acoustic pressure modulation signals in said two
chambers,
conduit means for transmitting said low frequency signals from at
least one of said two chambers in a direction toward at least one
ear of the wearer,
said conduit means comprising at least one tubular member having a
first end connected to said housing and a second end adapted to be
positioned in proximity to an ear of the wearer,
second output transducer means positioned adjacent said second end
of said conduit means,
means connecting said source of audio signals to said second
transducer means for driving said second transducer means and
producing high frequency audio signals therefrom,
a wearable member adapted to be worn on the torso of a wearer,
said housing and conduit means being attached to said wearable
member,
wherein when said system is worn with the housing being positioned
on the wearer's torso and the conduit means positioned with said
second ends adjacent the wearer's ears, the system provides to the
wearer a low frequency and high fidelity response which
approximates that provided by conventional head phones and ear
phones that cover the wearer's ears and significantly block
external sounds to the ears.
2. The audio system as set forth in claim 1 wherein said wearable
member comprises a garment selected from the group comprising a
vest, shirt, shawl, jacket, coat, sweater, sweatshirt.
3. The audio system as set forth in claim 1 wherein said conduit
means is made from a pliable material which is conformable to the
torso of the wearer.
4. The audio system as set forth in claims 1 or 3 in which said
conduit means comprises a first conduit member for transmitting
said signals to a first ear of the wearer and a second conduit
member for transmitting said signals to a second ear of the
wearer.
5. The audio system as set forth in claim 1 wherein said housing
and said conduit means are made from a material which is
conformable to the torso of the wearer.
6. The audio system as set forth in claim 1 in which said conduit
means comprises a first conduit member for transmitting said
signals to a first ear of the wearer and a second conduit member
for transmitting said signals to a second ear of the wearer, and
said second transducer means comprises a first transducer member
positioned in said first conduit member and a second transducer
member positioned in said second conduit member.
7. The audio system as set forth in claim 3 wherein said conduit
means is filled with an open cell foam material.
8. The audio system set forth in claim 6 wherein said first and
second conduit members are conformable to the torso of the wearer
and filled with a substantially acoustically transparent
material.
9. The audio system as set forth in claim 8 wherein said
substantially acoustically transparent material comprises an open
cell foam material.
10. The audio system as set forth in claim 1 wherein said source of
audio signals is positioned in a pocket of said garment member, and
said housing and conduit means are adapted to be integral parts of
said garment.
11. The audio system as set forth in claim 1 wherein said garment
member has a collar and said second end of said tubular member is
positioned in said collar.
12. A wearable audio system for producing broad-band high fidelity
audio signals to the ears of a wearer, the audio signals including
high frequency signals and low frequency signals, said system
comprising:
a wearable garment member for wearing on the torso of the
wearer,
a housing attached to said garment member and having two chambers
with a common wall member separating said two chambers,
a source of broad-band high fidelity audio signals in communication
with said housing,
first output transducer means mounted on said common wall member
for producing low frequency audio signals,
means connecting said source of audio signals to said first
transducer means for driving said transducer means and producing
said low frequency audio signals in said two chambers,
a first tubular conduit member for transmitting said low frequency
audio signals from one of said two chambers to a first ear of the
wearer,
said first tubular member having a first end connected to said
housing and a second end adapted to be positioned on the torso of
the wearer directed toward said first ear,
a second tubular member for transmitting said low frequency audio
signals from the second of said two chambers to a second ear of the
wearer, said second tubular member having a first end connected to
said housing and a second end adapted to be positioned on the torso
of the wearer directed toward said second ear,
second output transducer means positioned adjacent said second ends
of both of said first and second conduit members, said second
transducer means producing high frequency audio signals,
means connecting said source of audio signals to said second
transducer means for driving said second transducer means and
producing said high frequency audio signals therefrom,
said housing and said first and second tubular conduit members
being attached to said wearable garment member,
wherein broad-band high fidelity audio signals are transmitted to
the two ears of the wearer without said conduit members covering or
touching the wearer's ears or blocking environmental sounds.
13. The audio system as set forth in claim 12 wherein said garment
member comprises a garment selected from the group comprising a
vest, shirt, shawl, jacket, coat, sweater, sweatshirt.
14. The audio system as set forth in claim 12 wherein said housing
and two tubular conduit members are conformable to the shape of the
torso of the wearer.
15. The audio system as set forth in claim 12 wherein said two
tubular conduit members are filled with an open-cell foam
material.
16. The audio system as set forth in claim 12 wherein said source
of audio signals includes a cross-over network for separation of
the audio signals into the high frequency and low frequency audio
signals.
17. The audio system as set forth in claim 12 wherein said first
transducer means comprises at least two speaker members.
18. The audio system as set forth in claim 1 wherein two housings
are provided on said wearable garment member, each of said housings
having first and second transducer means and a tubular member,
wherein said two housings produce broad-band high fidelity audio
signals separately to the two ears of the wearer.
Description
TECHNICAL FIELD
The present invention relates to portable entertainment and
personal communication systems, particularly wearable audio
systems.
BACKGROUND OF THE INVENTION
There are many situations where it is desirable to provide audio
output for personal use to be worn or carried near the body. This
audio output could be used for portable entertainment, personal
communications, and the like. These personal and portable
communication and entertainment products include, for example,
cellular and portable telephones, radios, tape players, and audio
portions of portable video systems and personal monitors.
The audio output for many of these systems is typically directed to
the wearer through the use of transducers physically positioned in
the ear or covering the ear, such as earphones and headphones,
respectively. Earphones and headphones, however, are often
uncomfortable to use for long periods of time. Also, they can block
or attenuate environmental sounds causing the wearer to lose
contact with the surroundings. In this regard, this can compromise
safety considerations if the wearer is engaging in activities such
as running, driving a vehicle or operating machinery.
One common use of audio systems with earphones and headphones
involves exercise and athletic events. It is quite common to see
people running or exercising with headphones or earphones
positioned in or covering their ears. Not only is this dangerous
since the person often loses contact with external sounds and
surroundings, but the earphones and headphones are subject to being
dislodged as a result of the activity. Moreover, perspiration and
inclement weather could affect the integrity of the speakers and
audio system.
It is commonly desired to provide stereo audio output, i.e.
two-channel sound, from these portable entertainment and personal
communication systems. Stereo is particularly used for
entertainment purposes and for other applications of spatialized
audio. A stereo audio output may be provided without earphones or
headphones by arranging small loud speakers (a/k/a transducers) on
the body. The speakers, however, are not able to create broad-band
high fidelity sound, particularly in the low frequency ranges. In
this regard, loud speaker transducers are usually mounted in
enclosures to confine the acoustic radiation from the rear portions
of the transducer so that the radiation does not combine with
out-of-phase radiation from the front portions of the transducer.
Without such an enclosure, there is a significant reduction of net
radiated intensity, especially in the low frequency audio
ranges.
For wearable speakers, the requirement of an enclosure creates a
problem. In general, the volume of the enclosure will be quite
small and its acoustic stiffness will dominate the speaker
behavior. The result will be a high resonance frequency and
consequently a poor low frequency response.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
audio system for portable entertainment and personal communication
systems. It is another object of the present invention to provide a
portable audio system which provides high quality sound,
particularly at low audio frequencies.
It is another object of the present invention to provide a wearable
audio system which can be easily worn and does not interfere with
the person's activity, whether sports related or otherwise. It is a
still further object of the present invention to provide a wearable
audio system which does not require the position of the speakers to
be covering or inserted in the wearer's ears and thus overcomes a
number of the problems and drawbacks with present systems.
The present invention fulfills these objects and overcomes the
problems with known systems by providing a personal audio system
which provides high quality sound at all audio frequencies. In
accordance with the present invention, portable speakers are
provided which are wearable on the person's body and provide sounds
to the ears without the necessity of actually being positioned in
or covering the ears. With the present invention, transmission of
lower frequencies also is enhanced.
The present invention utilizes one or more sealed chambers, each
with two cavities, positioned to provide audio emissions to the
wearer's ears. The cavities are separated by a common wall on which
are mounted one or more transducers whose diaphragms communicate
directly with the two cavities. When the transducer is driven at
acoustic frequencies, it produces acoustic pressure within the
cavities.
In one embodiment of the invention, one of the two cavities is
sealed and the other has one or more tubular members or conduits
leading from it. The outer ends of the tubes are placed in close
proximity to the wearer's ears. In another embodiment of the
invention, conduits or tubular members are attached to each of the
cavities. The tubes lead from each of the two cavities and are
directed and positioned to provide audio sounds to each of the
wearer's ears.
Another embodiment of the invention combines the tube-sampled
system with separate high frequency transducers. Electrical
cross-over networks separate the signal frequencies into
appropriate channels. Where two conduits or tubes from opposite
sides of the dual cavity are utilized, the acoustic pressure is
180.degree. out-of-phase. In this embodiment, the acoustic
radiation is in the form of a dipole, and this reduces the net
radiation to bystanders.
The sampling chambers are preferably positioned on the torso of the
wearer, such as the chest, shoulders or lapel, and are either
hollow or filled with a substantially acoustically transparent
material, such as open-cell foam. The chambers are part of an
enclosure or housing which can be conformed or made conformable to
the wearer's body. The enclosures or housings also can be
integrated into various types of clothing, such as vests, jackets,
shirts or shawls as desired.
These and other objects, features and advantages of the present
invention will become apparent from the following description of
the invention when viewed in accordance with the attached drawings
and appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one embodiment of a sample chamber in accordance
with the present invention;
FIG. 2 illustrates another embodiment of the present invention;
FIGS. 3-4 depict alternate possible wearable embodiments of the
present invention;
FIG. 5 illustrates a cross-over network for use with the present
invention;
FIG. 6 illustrates a cross-over network for use with an alternate
embodiment of the invention; and
FIG. 7 illustrates a portion of a cross-over network for use with a
pair of sample chambers shown in FIG. 1.
BEST MODE(S) FOR CARRYING OUT THE INVENTION
It is desirable to produce frequencies on the order of 80 Hz or
less in order to achieve high fidelity performance comparable to
what is commonly available from inexpensive earphones. Small
enclosures of conventional design are unsatisfactory for this
purpose. Also, compensating techniques such as vented "bass reflex"
enclosures cannot be used for this purpose.
It is known that loud speaker transducers should be mounted in
enclosures to confine the acoustic radiation from the rear portions
or surface of the transducer so that it does not combine with the
out-of-phase radiation from the front portions or surface. If the
two radiations combine, a large reduction of net radiated intensity
results, especially at low frequencies.
The combination of transducer and enclosure behaves like a high
pass filter whose turnover frequency depends on several system
parameters. These parameters include the free-space resonant
frequency of the transducer, and the volume "V" of the sealed
enclosure which acts to produce a restoring force for the diaphragm
of the transducer. For small enclosures, such as those which might
be worn on the body, the enclosure stiffness is likely to dominate
the system. The system resonance in this region varies
approximately as .sqroot.1/V and the low frequency turnover point
becomes unacceptably high. For example, an enclosure whose
dimensions are (10 cm).times.(5 cm).times.(1 cm) would produce a
turnover frequency on the order of 600 Hz. Acoustical radiation
below that frequency falls at a rate of 12 dB per octave for
constant input. At 60 Hz, for example, the radiation is reduced by
40 db with respect to that above 600 Hz.
Transducers mounted on or in a sealed enclosure will exhibit
resonant behavior. The frequency of the resonance depends on a
number of parameters, principally the free space resonant frequency
of the transducer and the volume of the enclosure. At frequencies
significantly below the resonant frequency of the system, standard
speaker enclosures and transducers cease to radiate useful acoustic
power. At the same time, the transducer excursion for constant
input continues at nominally constant amplitude. Therefore the
acoustic pressure inside the enclosure can be sustained at a high
level below the normal resonant frequency even though the radiated
acoustic pressure is very small. The low frequency response inside
the enclosure is maintained well beyond the usual limit for
radiated sound.
It is to be understood that the term "transducer" used herein can
refer to a single speaker or an array of two or more speakers.
One embodiment for providing enhanced low frequency response for
wearable speakers is shown in FIG. 1 and designated by the
reference numeral 10. The chamber has two cavities 12 and 14 which
are separated by a common wall 16. One or more transducers 18 are
mounted on the wall 16 and the diaphragms of the transducers
communicate directly with the two cavities. When the transducer or
transducers are driven at acoustic frequencies, they produce
acoustic pressure within the cavities 12 and 14.
As shown in FIG. 1, cavity 14 is completely sealed (except for an
atmospheric pressure equalizing leak). The other cavity 12 has a
tube 20 leading to the outside serving as a conduit for sampling
the internal acoustic pressure. The acoustic pressure is presented
at the open end 22 of the tube 20. When the open end 22 is
positioned adjacent the ear of a wearer, the hearing of the low
frequencies of the system is enhanced.
One of the chambers 10 can be positioned adjacent each of the ears
of the wearer. Alternately, the tube leading from chamber 12 can
have two ends so one can be positioned adjacent each ear. This
alternative is shown in phantom lines in FIG. 1 with the second
fork of tube 20 labeled with reference numeral 20' and the second
end labeled with reference numeral 22'.
The chambers and tubes for the system shown in FIG. 1 (and for the
systems shown in FIGS. 2-4 described below) can be hollow.
Preferably, however, the chambers and/or tubes are filled with an
acoustically transparent material, such as an open-cell foam
material. This particularly enables the use of soft, flexible body
conforming wall materials.
A second embodiment of the invention is shown in FIG. 2. In this
embodiment, the sample chamber 30 has a pair of cavities 32 and 34.
The cavities are separated by a common wall 36 on which one or more
transducers 38 are positioned. Tube 40 has an open end 42 which
communicates with cavity 32. Tube 44 has an open end 46 which
communicates with cavity 34.
With the embodiment of FIG. 2, the ends 42 and 46 of the tubes are
positioned in proximity to the ears of a wearer. When the
transducers 38 are driven at acoustic frequencies, they produce
acoustic pressure within the cavities 32 and 34. The acoustic
pressure is then presented to the wearer's ears through the tubes
40 and 44. In the embodiment shown in FIG. 2, the acoustic pressure
will be nominally 180.degree. out-of-phase at the ends of the
tubes. In this regard, the acoustic radiation is in the form of a
dipole (or doublet). This reduces radiation at distances
significantly larger than the separation of the dipole sources. It
also reduces possible noise to bystanders, particularly at low
frequencies.
It is also possible to provide two or more conduits or tubular
members from one or both cavities of the chamber 30.
A further description of a dipole is contained in commonly-owned
U.S. patent application Ser. No. 08/400,901, filed on Mar. 8, 1995
and entitled "Portable Speakers With Enhanced Low Frequency
Response", the disclosure of which is hereby incorporated by
reference herein. The present application also should be considered
with the disclosure of commonly-owned U.S. patent application Ser.
No. 08/483,759, entitled "Sampled Chamber Transducer With Enhanced
Low Frequency Response" (attorney's docket number IRC 0119 PUS),
which was filed concurrently with the present application and the
disclosure of which is hereby incorporated by reference herein.
A known characteristic of chamber-tube systems such as the ones
described above, is that the tube and cavities form a resonant
system. This is commonly referred to as a Helmholtz resonator. The
resonant frequency "F.sub.R " is determined to first order by the
cavity volume, the length of the tube, and the diameter of the
tube.
At frequencies significantly below the resonant frequency, the
outlet pressure in the tubes is approximately equal to the cavity
pressure. There will be some attenuation, but for tubes with
diameters and lengths appropriate for wearable speakers, this loss
is generally negligible.
At frequencies above F.sub.R, the tube outlet acoustic pressure for
constant driver input falls at an asymptotic rate of about 6 dB per
octave, modulated by resonances in the tube itself. Since the
acoustic intensity is proportional to the square of the acoustic
pressure, the intensity falls at about 12 lb per octave.
For each system or sample chamber, there will be a turnover or
cross-over resonant frequency. Preferably the system is designed to
have a resonant frequency on the order of 100-200 Hz or higher.
One of the features of the present invention is that the
transducers which are employed to generate low frequencies within
the chamber do not have to have a particularly low free resonant
frequency. The overall efficiency of the system will be maximized
when the chamber and cavities are as small as possible consistent
with using a transducer or array with sufficient displacement to
yield desired output acoustic pressures. Since small cavities
produce high turnover frequencies, the individual transducers need
only have resonant frequencies which are lower than the turnover
frequency of the system. In this regard, the cavity volumes will
generally dominate the determination of the resonance of the
system.
The transducers and systems of the present invention are used to
convey audio signals from various known electronic acoustical
devices and convert them to audio transmitted to the wearer's ears.
These devices include, for example, AM or FM radios, cassette tape
players, CD players and cellular telephones.
In a preferred use of the present invention, the sample chambers
are combined with separate high frequency transducers in an audio
system. As indicated above, the sampled chambers create a
preferential transmission of the lower audio frequencies and
provide satisfactory sound at all frequencies. If desired for
better high frequency sounds, the additional transducers can be
provided.
A combined system is similar to "satellite" loudspeaker systems in
which a low frequency unit, often called the "woofer", or
"sub-woofer", driven monaurally, is complemented by two high
frequency units driven in stereo. A system of this type is shown in
FIG. 3 and designated by the numeral 50. The embodiment of the
invention 50 is shown being worn by a wearer 52. The system 50 has
a single two-cavity chamber 54 configured in the form of a pendant.
This is worn with a "yoke" which has within it a pair of tubes 56
and 58 integrated in the form of thin flat narrow structures. Ends
57 and 59 of tubes 56 and 58, respectively, are open and have
roughly rectangular cross sections. Ends 57 and 59 are positioned
near the shoulder or collar of the wearer adjacent to the wearer's
ears. Tube cross sections of other geometries, e.g. circular or
ellipsoidal, may also be used.
The chamber 54 contains either a single transducer or an array of
smaller transducers 55. The transducers are attached to a common
wall in a manner similar to that shown above with respect to FIGS.
1 and 2.
A pair of high frequency transducers or arrays of transducers 60
and 62 are positioned at or near the open ends 57 and 59 of the
system 50. The transducers 60 and 62 should be oriented or pointed
toward the wearer's ears for maximum efficiency. It is also
possible for the high frequency transducers to be mounted in other
places on the wearer's torso or garment, such as on the collar.
An electrical cross-over network is used to separate the signal
frequencies into the appropriate channels for the system 50. A
representative network is shown in FIG. 5. In this regard, any
subsidiary resonances in the tubes will not have any deleterious
effect because there is not any significant driving signal at those
frequencies. Nevertheless, however, it is desirable to provide
additional dampening or compensation of the tube resonances for
increased performance.
As shown in FIG. 5, the right "R" and left "L" stereo audio signals
are each sent to frequency band splitters 100 and 102,
respectively. The right audio signals are split into a first
frequency band 104 which are the lower frequency signals, and a
second frequency band 106 which are the higher frequency signals.
The higher frequency R signals are amplified by amplifier 108 and
used to drive "tweeter" speaker 110. Similarly, the left audio
signals are split into a first frequency band 112 which are the
lower frequency signals, and a second frequency band 114 which are
the higher frequency signals. The higher frequency L signals are
amplified by amplifier 116 and used to drive "tweeter" speaker 118.
The R "tweeter" 110 is positioned near or adjacent to the right ear
of the wearer, while the L "tweeter" 118 is positioned near or
adjacent to the left ear of the wearer.
The two low frequency band signals 104 and 112 are combined by
summer 120 and fed to amplifier 122. The combined low frequency
signals are then used to drive speaker or transducer 124. As
indicated in FIG. 5 in phantom lines, the transducer 124 is
positioned in sampling chamber 54' and the acoustical signals are
directed toward the wearer's ears by tubular members or conduits,
56' and 58'. In this manner, the wearer receives the full range of
audio signal frequencies. In this regard, in this embodiment, the
sampling chamber is similar to chamber 30 as shown in FIG. 2.
FIG. 6 illustrates the use of a sampling chamber similar to FIG. 1
with the system shown in FIG. 5. In FIG. 6, the R and L high
frequency tweeters 110 and 118 are the same as those described
above. For the low frequency bands, however, the sampling chamber
10' contains two chambers (one of which is sealed) and a forked or
split tube 20, 20' which direct the audio signals to the wearer's
ears by tube ends 22 and 22', respectively.
Another embodiment of the present invention uses enhancements to
generate or improve the higher frequencies of the system. This
could be accomplished by means of equalization, that is, driving
the transducers harder at frequencies above the turnover or
resonant frequency. Equalization may also be employed to suppress
undesirable resonances.
FIG. 4 shows an alternate system for utilizing the present
invention. In this system 70, two separate chamber systems 72 and
74 are provided, one for each of the ears of the wearer. Chamber
system 72 has a sample chamber 76 and a sample tube 78. System 74
has a sample chamber 80 and a sample tube 82.
Each of the chamber systems 72 and 74 are two-cavity systems
similar to that described above with reference to FIG. 1. In these
systems, one or more transducers are attached to a common wall
separating the two chambers. One of the chambers is sealed and the
other is in communication with its respective tube 78 or 82.
With use of the system shown in FIG. 4, the sampling tubes 78 and
82 preferably are positioned so that they are vertically parallel
to the wearer's neck and in close proximity to the ears. In this
regard, the ends 84 and 86 of the tubes 78, 82 are open allowing
the acoustic pressure to be presented directly to the wearer's
ears.
In a combined system, high frequency transducers 85 and 87 are
positioned in the open ends 84 and 86 of the tubes 78, 82. The two
systems 72 and 74 are connected electronically by wires or the like
(not shown) and act together. This system also utilizes a
cross-over network similar to that shown in FIG. 6 and discussed
above. However, as shown in FIG. 7, the signal from the amplifier
122 is sent to the transducers in the chambers 76 and 80 of the two
systems.
As indicated in FIGS. 3 and 4, the present invention is adapted to
be worn by the wearer during normal activities. In this regard,
although the systems 50 and 70 are shown as independent entities,
they preferably are integrated into a wearable garment of some
type, such as a vest, jacket, shirt, shawl or the like. With a
shirt having a collar, the open ends of the tubes of the systems 50
and 70 are preferably positioned at or near the upper edge of the
collar.
The type of garment utilized would depend on the individual
utilizing the system, as well as the appropriate needs of fashion
and other considerations, such as whether the garment has to be
used for other purposes, (e.g. carrying additional items). A vest
with a number of pockets or sections to hold the audio device, as
well as the sample chamber or chambers and the tubular members,
would provide a satisfactory garment for use of the present
invention.
Although particular embodiments of the present invention have been
illustrated in the accompanying drawings and described in the
foregoing detailed description, it is to be understood that the
present invention is not to be limited to just the embodiments
disclosed, but that they are capable of numerous rearrangements,
modifications and substitutions without departing from the scope of
the claims hereafter.
* * * * *